Roar with laughter (6)
I believe the answer is:
guffaw
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">roar with laughter</span>' is the definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for guffaw that I've seen before include "A loud uninhibited laugh" , "Roar of laughter" , "Laugh loudly" , "coarse laughter" , "Crude and boisterous laugh" .)